Can We Fix Wireless in Health Care?

Awareness is growing about the challenges of developing and maintaining safe and effective wireless medical devices. What with IEC80001 moving forward (due to be finalized next year) and the recent series of wireless medical device workshops, people in hospitals and among vendors are asking more of the hard questions about wireless. Amongst the turmoil, participants are jostling for position. This post looks at common problems with Wi-Fi, a report from U.K. alliance ERBI, and some alternatives to Wi-Fi.

Problems with Wireless

Those of us who are old enough, think back to the golden age of wireless medical devices — channelized analog telemetry. These systems were so basic and limited in scope (a couple dozen transmitters typically covering just a single 30 bed unit) that they had few problems and required little maintenance.  Today, larger hospitals are pushing the envelope with a few hundred patient monitors and a thousand or more wireless infusion pumps. These wireless devices are using sophisticated client radio/access point (AP) communications protocols to maximize capacity, whether using Wi-Fi or WMTS. We’ve since left the golden age far in the past.

Radio frequency (RF) spectrum is a shared resource. There’s no getting around that fact, even with “dedicated” spectrum. The ether in which wireless signals move is like gases in the atmosphere or chemicals in water. There are no ways to practically segregate RF signals to specific areas, except for a Faraday cage. In a health care facility, some shielded rooms in Radiology qualify as Faraday cages, but little else. Much of the rest of a health care facility consists of objects and structures that seem to perversely confound and obstruct RF communications in  ways like partially blocking and attenuating signals, creating multipath interference, and radiating both intentional and unintentional interference. Intentional interference is where two or more users of a portion of wireless spectrum get in each others way, disrupting or degrading the communications of one or both parties. When there are problems with two or more wireless devices using the same spectrum, this is intentional interference, often referred to as coexistence problems. Unintentional interference comes from electromechanical devices that accidentally spew RF signals as a consequence of some degradation or failure. Common sources of unintentional interference are florescent light balasts, blow dryers, paper shredders, elevator motors, or faulty microwaves. You can see a bunch of examples of RF interference on a spectrum analyzer (which everyone doing wireless medical devices should have, and know how to use) here.

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Philips to Acquire VisICU


Philips announced yesterday that they reached a merger agreement to acquire VisICU for $12 per share, $3 over the current share price. From HIStalk, “Visicu earned $9 million on sales of $36 million over the past year. In
the 20 months since its IPO, Visicu shares have dropped from nearly $25
to below $9. Its board has approved the acquisition and recommends that
its shareholders approve it.” VisICU also had $130 million in cash on their balance sheet at the time of the agreement. The value of Philips’ offer totals around $300 million.

The Philips’ press release describes their rationale for the purchase.

By integrating VISICU’s remote patient monitoring and clinical
decision support technology with Philips’ patient monitors, both
companies expect to accelerate growth by offering products that provide
more effective clinical decision support to hospital staff, while
allowing them to monitor far greater numbers of critically ill patients.

Sounds like an extension to the old “proprietary end-to-end solution” strategy. The VisICU service would seem a natural extension for their ICU monitoring business. Tighter integration could probably improve performance and usability. Whether that would translate into better patient outcomes is questionable.

Rumor has it that Philips has one more acquisition to announce before the end of the year.

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Philips Launches Wireless Monitor/Defibrillator


Philips does it again, with an announcement that is sure to cause consternation among their competitors (press release). Philips has launched a wireless version of their HeartStart MRx monitor/defibrillator. The device will run on 802.11a/g wireless LANs, “with [the] capability to network with the Philips IntelliVue Clinical Network.” The press release starts off talking about workflow and clinical benefits:

Using the HeartStart MRx, hospitals will be able to transport patients who require cardiac monitoring or therapy between departments or within the same unit without changing equipment. The MRx can also be used at the bedside in departments that would benefit from having both centralized surveillance and cardiac therapy at their fingertips.

There are two big markets for monitor/defibrillators, hospitals and ambulances. While wireless connectivity in the EMS (emergency medical services) world has been around for some time, adoption is severely hampered because hospitals and EMS providers are separate entities. Given the propensity for vendors to create proprietary end-to-end solutions, pre-hospital connectivity necessitates that numerous independent hospitals, and the EMS providers who serve them, must use monitor/defibs and hospital based clinical information systems from the same vendor. Sadly, the structure of the pre-hospital EMS market, and the proprietary strategies of device vendors, has resulted in just a few high profile beta site/trials (that demonstrated meaningful improvements in patient outcomes) and a smattering of adoptions. The return for vendors on their R&D costs for developing this connectivity has been less than poor – not that they can blame anyone but themselves.

In the hospital, monitor/defibs have been standalone devices used in emergency situations. Of course there’s been a need for connectivity (data capture, surveillance and alarm notification) all along. The absence of connectivity has made it possible for a standalone company like Zoll to grab a piece of the hospital market. With the advent of wireless connectivity for the HeartStart MRx, Philips has a powerful new competitive differentiator. Philips is now the only vendor with both full line patient monitors and defibrillators integrated via connectivity into one system – this will be a big deal. GE now has a reason to go buy a defibrillator company. (Maybe Physio-Control, I hear they’re for sale.) Patient monitoring vendors without defibrillators will have another lock-out spec to fight. And defib companies, like Zoll and CardiacScience, will slowly and irretrievably lose hospital market share. Could there be a whole round of defib company acquisitions in the near future?

This tactical move by Philips is shaping up to be an example of leveraging connectivity for competitive advantage. Unfortunately there are few such examples – a hesitancy to adopt connectivity and poor strategies and execution have plagued many vendors. The words, “you don’t know what you don’t know” were never truer then when referring to medical device connectivity.

Pictured right is the Philips HeartStart MRx.

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Day One at AACN/NTI

New Orleans

It is hot and sultry here in New Orleans. Heard some great blues last night. But I really have been working. Here’s what I came across today. Hospira released their MedNet system — I’d tell you more, but the press release didn’t stay out too late last night.

Emergin was once again the vendor who was everywhere, but had no booth. They were in the Spacelabs, Alaris and Philips booths providing the software for alarm management and communications. As an aside, Philips introduced two new monitors at this show; I’ll go by tomorrow and check them out.

Welch Allyn introduced a new monitor, the Propaq LT. Here’s part of their 510k submission. More on this later.

B Braun wasn’t at HIMSS so I haven’t done a write up of their smart pump yet. They’ve wirelessly enabled their 100, 200 and (at this show) their 300 pumps. They will complete the line with the 400 by the end of this year. Here’s a story from 2002 on both Alaris and B Braun smart pumps — you will get a feel for how long they’ve been at this (since 2001) and how well they’ve delivered on their promises.

It’s almost time for dinner. Welch Allyn, the sponsor of our Sunrise Session tomorrow, is talking my co-presenter Cheryl Batchelor and I out tonight. The good news it’s a good creole restaurant, the bad news is I can’t wear shorts.

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Philips Telemetry to Use New Hospital WLAN Technology

According to an updated page on their website, Philips has abandoned their “channelized” radios for a frequency hopping, bi-directional, spread-spectrum WLAN in the WMTS band.  They’ve joined GE and Datascope with similar WLAN technology in WMTS. They couldn’t resist coming up with their own name, so they’re calling it “Smart-hopping Technology.”  From this diagram, it seems that they’re using a private LAN connecting their access points to their central stations.  Apparently they can bridge to the Hospital LAN at the central station or a server for HL7 connectivity.

This means that for all of you who recently upgraded your Philips Telemetry system to move to WMTS, you will need to install a new network infrastructure that duplicates the antenna system of the older channelized system if you expand your system.  There is no press release or other information offering any more details at this time.

[Update]  I got a nice email from a contact at Philips who said that Philips has not publicly announced their new telemetry network (although the page is still up on their site).

[Update]  More info on Phiip’s new wireless network.  They will continue to offer their channelized radios (in the 608-614Mhz band) for traditional Telemetry deployments and international markets.  The new network uses the upper 1.4Ghz WMTS band, and with greater capacity for networkd devices, is geared for hospital-wide monitoring deployments.

Philips has developed a component radio module that can be integrated into a range of monitors.  The radio and APs are based on the DECT protocol (Digital Enhanced Cordless Telephoney).  This standard from Europe is used for private wireless phone systems, like SpectraLink phones.  PMS is leveraging a core competancy in DECT technology that Philips corporate has developed. You can find an introduction to the standard here (requires registration – email me and I’ll send you the .pdf).  They chose DECT because, like voice, continuous monitoring requires requires low latency and virtually no dropped packets.

Leveraging DECT provides an industry standard, with associated economies of scale and robustness.  However, by creating their own WMTS implementation of DECT, Philips has created a proprietary network. Change vendors and some of the network infrastructure will have to be replaced. Multi vendor coexistance at 1.4Ghz is also a question.

The radio is currently integrated into their telemetry monitors, but won’t be available in multi parameter monitors until this summer. Current capacity of the network is 128 devices. This will be expanded to 512 devices by this summer, and is theortically expandable beyond 512.

Infrastructure is made up of (from the edge in) access points (APs), controllers (thin APs?) and switches.  The APs are power over Ethernet (POE) where power and network connection are on the same wire.

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